Universal joint



July 3, 1951 l A. BOGE, sR., ET Al. 2,559,108

UNIVERSAL JOINT Filed Sept. 25, 1949 Patented July 3, 1951 UNI-rizo armes; PATENT oFiflci.y

UNIvEnsAL JQINT 1 Adolf Boge; Sr., Altgluck, and AdolfBoge, Jr., i Eitorf, Germany.

Application September 23, 1949, Serial No..11 7,431

' I n Germany October 1,1948

Among the various knownforms of- Cardan joint are those in which a` centre-piece is both rckable and axially slidable Within a housing. Infthiscentre-piece'the Cardan-stub ofthe driven shaft is rockable on an axis which is; at right; angles both to the longitudinal axis of the casuing,vr in Which direction sliding cantake place, ancilv to the rocking axis of the centre piece; It has been found that such jointsare inclinedA towear excessively. Forl thisreasonit'zhas been proposed to" provide the centreepiecejwith trunnions on its rocking axis and to journalthese inV slide-blocks, so that' the sliding movementis executed; by the slide-blocks alonek andthe rockingmovement ex'- clusively by the centre-piece in the slid'eeblocks. An advantage was expected from the fact that' the transmission of force novvv nolonger, took place with slight tilting exclusively' at tvvol diagonally opposite longitudinal edges' of the centre-piece;` but that it was possible tobring `the surfaces of the s lide'blocks into use at the same time to transmit forces and'so to distribute the lineazontactobtained hitherto over comparatively large surfaces. This proposal hasnot come into practical use becausel on one hand the machining costs are relatively high and on the other hand because accuracy could not bev achieved: to the degree necessary to ensure that'both the' centrepiece and the slide-blocks took part* in..vthe transmission of forces. avoid transmission of forces frorrrV the centrepiece toy the housing andto ltransmit the rota. .-v tion from the housing throughthe slide-blocks alone to the centre-piece., But then the ,old rfault would have reappeared, for the, in thiscase smooth, guide surfaces of the slide-blocks and the corresponding guide groovesin the housing wouldn have tended to Wearand no advantage would'have been obtainablein thisway alsa-.the provisionof'the ends'urface of the slide-blocks and trunnions in relation to the housing as Well as of the corresponding surfaces of the housing was not quite simple in so far as these parts again Were to be cylindrically formed and also these surfaces are diiiicult to machine. Such a construction is described in German Patent No. 7,323,346.

According to the present invention in contradistinction to the last mentioned construction, transmission of forces through the centre-piece and slide-blocks is avoided and, as already indicated, the rotational movement is imparted exclusively through the slide-blocks and thence transmitted to the centre-piece. At the same time this is done in a particular way in that the It would have seemed obvious -to- J 2 Claims. (Cl'. 64118) slideeblocks areprovided each` with two guide groovesof circular profile which extend'l in thel direct-ion of longitudinal sliding. To theseguide grooves correspond pairs ofi? cylindrical rodsfwhi'ch, are arranged` in the casing and serve to= guidethe slide-blocks.

The advantagesto' be obtained from this arrangement arein the rstplace that allm`ove ments in the joint without except-ion can take:- placel on surfaces of turned" form; i. e. surfacesof-revolution- Thus, as in the hitherto lmo'vmJ joints, the rocking movements of` the Cardan stub-in the centre-piece'is-made p'oss-ible-byabolt orpivot traversing the centre-piece, which ena-f gages corresponding bores in the centre-piece:

and'iny the Cardan stub; Bores as-Well-as-thef boltcan be produced Wit-h the greatestaccuracy and maintenance of dimensions-Gambe satisfaceV torilyI verified inma'nufactureA by the simplest means: The rocking movementsV of thecentre piece in the'slide-blocks isagain made possible byj trunnions of cylindrical form engaging incorre= spending bores in the slide-blocks, andhere again?- the dimensions of the parts' and h-ighoualityl of thesurface can be achieved'in full measurein production. According' to vthe invention ,thesame also appliesv to the longitudinalY sliding? of* the slider-blocks inthe casing in sofar as thegrooves in the slide blockscan be directly producedr asl bores'and `thereafter the generallyprismatic slide blocks parted off; e. g. from a bar; Alsov the. corresponding rods to be mounted'inthe casing can be made with the highest accuracy andsubsequently insertedin the casing;

Transmission offorces takes place during lonu gitudinal slidingsolely between the corresponding.V

cylindricalsurfaces ,of the pins andthe slidlf blocks, so that al1' other surfaces of'thes1ide. blocks' can be left' rough machined. with thelnecese sary clearance in relation to the neighbouring parts. The bores in the slide blocks to receive the trunnions of the centre piece are naturally, as already mentioned, to be machined with the highest accuracy.

The high accuracy in the machining of the surfaces and the possibility of free choice of material permits high loading. In consequence, it is in no Way essential to preserve the prismatic form of slide-block used hitherto. On the contrary instead of such blocks, blocks of circular form, in eiect slide-rollers, can be used. These have the advantage on one hand that the friction is reduced and the mechanical efficiency of the joint is therefore increased, and on the other hand that the sliding surfaces Wear out less rapidly because new points on the roller peripheries are always being presented to the guide rods. This applies particularly to motor vehicles in which the direction of rotation and of force transmission is frequently changed so that the position of the slide-rollers in relation to the trunnions of the centre piece is also frequently substantially changed. v

A further advantage of the construction in accordance with the invention is that the material of which the two parts, not in particular the rods.r

is made can be of any desired high quality without the cost of production of the joint being substantially increased. The guide surfaces for the slide-blocks hitherto known were necessarily of the material f the housing and economy prevented a free choice of material. This also imposed limitation on any treatment which could be given to the surface. AOn this score also the the invention distinguishes from the construction hitherto known in that the rods can be hardened or otherwise improved without impediment. Finally it should be mentioned that the use of guide vrods has the further advantage that they can be replaced as soon as they no longer hold up to their dimensions.

The fastening of the rods in the housing can be effected in various ways. That it is possible for them to t tightly at their ends in the bottom and cover of the housing on cylindrical or conical surfaces. Or they can be provided with screw threads and be screwed into these parts. They can at the same time be used as anchors to hold together the cover, side wall and bottom of the housing. They can further be provided with eccentric parts at the ends and the advantage is then obtained that the rods can be rotated to give the correct spacing. Y Y

, In effecting such rotation care must be taken that the slide-blocks` guided by them are not canted over, it being unimportant however whether the slide-block is moved bodily a little more or less along the corresponding trunnion of the centre-piece because here ample clearance can be allowed without difficulty. With noneccentric mounting it is further possible to turn the rods into some three different positions, enablingthe workingsurface to be changed for instance, if the sliding surface are damaged by dirt entering through faulty sealing of the joint.

,. An example of the invention is illustrated in the accompanying drawing,

housing. A s'pherically turned centre-piece 8 has at its ends trunnions 9 by which it is rockably journalled in slide-blocks I0. These slide-blocks are of generally rectangular prismatic form and on their end surfaces have adequate clearance in relation to the centre-piece 8 and the housing wall Il. They are guided only in relation to the rods 'I by ground guide grooves I2 and the rods 'I also have ground surfaces.

In the centre-piece is a rectangular, central, longitudinal passage I3 in which ts the end I4, constructed as a bearing, of the Cardan stub I5. The pivoting of the stub I5 in the centre-piece 8 is eifected by a pivot pin I6 which is pushed into a corresponding bore in the centre-piece 8. The Cardan stub I5 is secured to the shaft l1 and the housing 9 at the end of its wall II is sealed o by a push-on sheet metal cover I8 and a rubber cuff I9, so that the housing can be filled with oil.

YThe construction of the individual parts can be varied without departing from the invention. Thus it is possible without any difliculty to fabricate the housing, e. g. by making a coupling ange of plate, a bottom of pressed sheet and a Wall of tube and connecting these parts together by welding, instead of making the housing as an iron casting.

We claim: l

l. In a universal joint, the combination of a Cardan stub, a centre piece rockable on a first transverse axis on said stub', trunnions on said centre-piece set on a second transverse axis at rightangles to said rst transverse axis, slideblocks rockably journalled one on each of said trunnions, a housing, and four longitudinal cylindrical guide rods set in two pairs in said housing,

said slide-blocks each having guide grooves of circular profiles whereby they slidably engage the respective pairs of guide rods.

2. A universal joint as set forth in claim 1 wherein. said slide-blocks are of substantially rectangular prismatic form. I

ADOLF HOGE,l SR. ADOLF BOG-E, JR.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

